Means for protecting ships at sea



Get. 16, 1945. N. M. HOPKINS 2,386,950

MEANS 'FOR-PROTECTING SHIPS AT SEA Filed Jan. 20, 1943 6 Sheets-Sheet loct. 16, 1945. N, M HoPKlNg 2,386,950

MEANS FOR PROTECTING SHIPS AT SEA Filed Jan. 2o, '1945 e sheets-sheet 26 Sheets-Sheet 3 lq Q gwoon/bwa Oct. 16, N45.

N. M. HOPKINS MEANS FOR PROTECTING SHIPSl AT SEA Filed dan. 20, 1943 0d.16, 1945. I N, M, HOPKlNs 2,386,950

MEANS FOR PROTECTING SHIPS AT SEA Filed Jan. 20, 1943 e sheets-sheet 4MMHQPW Attorney Oct; 16, 1945.

N. M. HOPKINS MEANS FOR PROTECTING SHIPS AT SEA 6 Sheets-Sheet 5 FiledJan. 20, 1943 oct, 16, 1945.

N. M. HOPKINS MEANS FOR PROTECTING .SHIPS AT SEA y Filed Jan. 20, 1943 6Sheets-Sheet 6 Patented Oct. 16, 1945 sepia MEANS FOR PROTECTING SHIPSAT SEA Nevil Monroe Hopkins, New York, N. Y.; Raymonde B. Hopkinsexecutor of said Nevl Monroe Hopkins, deceased Application January 20,1943, Serial No. 473,010

19 Claims.

This invention pertains to new methods, ways and means of protecting thehulls of ships against submarine discharged, and plane launchedtorpedoes, and certain types of mines, the magnetic mine in particular,under all normal conditions of Wind and sea, this invention comprisingnot only the protection to a ship equipped against the magnetic mine,but also the protection to a ship following in its wake, by means of amagnetic loop towed astern.

It is an exceedingly important major object of this invention to providedeep torpedo protection and deep magnetic mine protection, through netorbelt-like devices and equipment capable of navigating with the ship,well below the roots of waves, for several vitally important reasons-toyavoid being smashed by the forces of the Wind and seaiand to reachdeeply moored magnetic mines and deeply launched magneticwarhead shtorpedoes, for example.

It is also an important object oi the invention to carry the protectivebelt equipment farther from the hull of the ship than heretoforepossible with booms and paravanes, thereby giving protection against themost powerful supertorpedoes now in use or in the making.

It is also an object of the invention to provide Counter-magnetic mineelectro-magnetic fields well in advance of a ship in times of gale, whenradio controlled surface launches or aeroplanes electro-magneticallyequipped could not operate.

It is also an important object of the invention to provide a barelyfloating electric towing sh" device and a barely iioating net or beltdevice when at rest in the water of the sea, both fashioned to be sent,by remote control from the protected ship, to one or more depths belowthe surface of the sea at Ia predetermined speed of navigation, throughaquaplane means, capable of slowly stopping or turning aside a iishtorpedo without exploding it, and therefore protecting the hull of aship against one or more torpedoes launched successively, one behind theother.

It is also an important object of the invention to provide novel designsvof counter-balanced, motor operated winding drums for the cables of thepower and wired radio control circuits, capable of insulating the cable,and yieldably paying out and anchoring the cable, respectively, and ofcontrolling the .angle of leads of the cables with the sides of theship, to control the pull of the electric fish by speeding up orretarding them. Therefore, there is contemplated the steering of theelectric lish and the maintenance of belt position in the sea, as wellas the depth and speed 55 control. of both, tension on the cables, andthe provision for comparatively small angles of cable lead from ship toelectric fish, in order to establish and maintain a minimum of lateralcable drag in the sea as well as to conserve useful deck space forcargo.

It is a further object of the invention to employ wired, or guidedradio, some times called carrier current radio for the control of the"electric fish from the ship using the angular displacement of thewinding drum carriages, as well as the power cables for the purpose.

I-t is also an object of the invention under certain conditions toemploy the wired or guided radio for purposes of remote controlusingboth the cables and the salt water of the sea as conductors for thecarrier currents.

With the foregoing objects in view, as well as certain additionalobjects made possible by modern engineering methods, which will becomeapparent as the description proceeds and the draW- ings are studied, theinvention resides in the novel and useful designs of apparatus andcombinations of apparatus and equipment, as well as scientificprinciples all as hereinafter set forth and particularly covered by theclaims.

Referring to the accompanying illustrations forming a part of thisspeoiiication and in which like numerals designate like parts in all theviews:

Figure 1 represents in partial vertical longitudinal section and partialelevation, one design of my electric iish for comparatively quickmanufacture using standard types of electric motors, for the towing of asubmerged anti-torpedo belt for ships at sea, and/or an electricalconductor for establishing a magnetic field for exploding magnetic minesplanted in the Sea.

Figure 2 is a side view of this electric iish in elevation.

Figure 3 is a partial horizontal longitudinal section and partialelevational top or plan View of this sh.

Figure 4 is a top plan view of a small cargo vessel under way, equippedwith one design of my submerged electric fish, belt device, windingdrums and other devices of the system for protection against torpedoeslaunched by aeroplane or discharged by submarine, with its possibleauxiliary anti-magnetic mine feature.

Figure 5 is a side view of this cargo vessel underway, so equipped,indicating the sub-sea surface navigation at one possible selecteddepth, of the combined electric iish and protective belt.

Figure 6 is a side view in partial section design of one of my stanchionsupported yieldable, motor operated winding drum for angular control ofmultiple cables, tension regulation, and the like in the water of thesea.

Figure 7 is a top plan view of this drum device in partial section.

Figure 8 is a top plan View of a small cargo vessel under way, equippedwith an alternate design of my submerged electric sh, simplied cable andwinding drums therefor, torpedo protective belt device andanti-submarine development.

Figure 9 illustrates an alternate magnetic mine-sweeping plan.

Figure 10 is a short section of one design of my barely oating compoundcanvas sheathed antitorpedo nets, cut through the center to save spacein its illustration.

Figure 11 is a transverse sectional view of the net, taken as on theline II-l I of Figure 10.

Figure l2 is a short section of the lower edge of this device, showingin section one of my automatic depth controlling aquaplanes, withschematic indication of an electro-magnetic remote control gear forchanging the depth of'navigation at will.

With further reference to Figure 1.

25 represents a small submarine boat or electric fish fashioned to leada ship at sea and be electrically operated by remote electric power.This electric power, transmitted through cable from the ship itprotects, is greater than any source of power possibly inherentlygenerated in the fish The power required has not only been calculatedfrom skin friction and other engineering data, but checked by actualexperiment and reduction to practice with rnodels. The electric lish hasalso been carefully calculated to have a positive buoyancy when at restin the salt water of the sea at a suitable temperature, and fashioned tobe forced below the surface of the sea to automatically regulated andadjustable depth by suitable aquaplanes and gear devices when under waywith its cable loads and other factors,

Here 26 and 21 are standard commercial electric motors, drawnsubstantially to scale, connected directly to the propellers 28 and 29for right and left hand drive, respectively, through customarycouplings, shafts, stufling boxes and thrust bearings, therebyeliminating any undue tendency to rotate the electric fish about itslongitudinal or major axis. What slight rotating torque one motor andpropellor may have over the other being cared for by a proper stabilityof the iish due to a suitable metacentric height of the whole structure,secured through the agency of the buoyant superstructure 30 and themetal ballast castings 3l, 3|, as well as the placing of certainauxiliary motors, 35, 43, 52, 48, and gear as shown below the centralaxis of the casing 25. The size of this electric sh, here illustratedroughly to dimensions, is of the order of 40 inches in diameter and 32feet overall length, has a sea water displacement of about 13,000 poundsand houses and oats a pair of three hundred horse power motors.

When the electric sh is confined to the towing of an anti-torpedo beltdevice as later illustrated and described, the motors 26 and 21 may beof the simple induction, squirrel cage type using three-phasealternating current, but when for the combined purpose of towing thebelt device and a countermagnetic mine loop the motors are preferably ofthe direct current, series connected design as indicated partially bydotted lines indicative of commutators and the necessary brush gear.These motors 25 and 21 may well be of railroad type Where the armaturesand elds are series connected, for example, or they may be of universaltype for either direct or alternating current with laminated elds inseries with armatures, each having a speed of 1800 R. P. M. In analternate design I have planned for two motors, one with a hollow shaftgear, for example, to enable me to have the pair of turbine typepropellers at the stern of the fish instead of one fore and one aft, asillustrated here, but I have compromised in this design to enable one toquickly use standard motors-for the purpose to save valuable time insecuring them.

In this design of electric iish the rudder 32 is placed at the bow, inorder to give powerful Steerage, since the pull of the protective beltcable is well aft and a rudder at this zone would be less eifective dueto the tension there. This rudder is turned by the quadrant of the bevelgear 33, by the bevel pinion 34 and the reversible electric motor 35.The rudder post 32 is conveniently supported in the open bell end 33which is fashioned rto guard the propeller and at the same time to allowthe water of the sea to flow freely through. It may be pertinent tostate here that by giving the bell end a bell flare by increasing itsdiameter just ahead of the leading propeller, increased duty is imposedupon it. Since this electric sh is in eilect a submarine, there islittle danger of surface oating debris getting into the leadingpropeller. Small iish would be quickly cut to pieces, but as previouslystated this design has been illustrated. to bring out the The electricmotor 35 may of course have addi-Y tional reduction gear between itsshaft and the bevel gear 34 and is fashioned to rotate clockwise orcounterclockwise at will, receiving current through step downtransformer or storage battery (not shown), and controlled by a set ofrelays, wired radio filters, ampliers, reversing switches and the like(not shown), all responsive to carrier currents generated by oscillatorson the convoyed ship and sent over the powervcable by automatic switchgear on the angle controlling winding drum presently illustrated anddescribed in detail.

It is well known that radio waves may be guided by metallic conductorsbetween a transmitter and a receiver insteadl of being allowed toradiate freely through space. This system therefore is ideal 'for thepurpose in hand. As a matter of pertinent collateral interest in thisconnection, it may be stated that energy waves may thus be transmitteddistances up to twenty times as great as those attainable Without theassistance of the guiding cable. Conversely it is obvious now that forshort distances greater power is available for the control. With properselection of radio frequencies between, let us say, 20,000 and 500,000cycles, there is absolutely no interference with the low frequency ofthe current in the power cable, which may be of the to use conductors ofthe power cable, whether of alternating current or direct current type,for carrying diferent power impulses at one time, each power impulseusing one of the selected frequency channels. These power impulses, ofcourse, amplied at the electric iish for any number of duties apart fromthe all important one of steering. Among collateral duties which may beimposed may be mentioned Variable depth control of the electric iish tomeet the requirements of variable wave height and depth of root. Radiowave energy has been successfully transmitted over telephone, telegraphand lighting circuits, trolley lines and power lines of all kinds formany years. Applicant has the promised co-operation of a nationallyknown radio engineering design and manufacturing corporation for thereducing to practice of .his remote control by carrier current of theelectric sh. 'Complete wired radio diagrams not sh'own.

The depth controlling aquaplane 36 shown in dotted lines in the presentview is controlled as schematically represented by the compressionspring 3'! and the pressure of the water of the sea, respectively,entering the opening 38 in the open base of the metal bellows 39, andthe guided piston 40 and the double lever gear 4I on th'e aquaplaneshaft 42.

vThe electric motor 43 is, like the steering motor 35, fashioned toreversable switch gear and relay operation by carrier current and wiredradio as previously set forth, for giving the fish a variable depthnavigation. From an inspection of this gear it will now be appreciatedthat the power of the spring member 31 may be increased or decreased atwill by remote wired radio control by the operation of the motor 43whose long threaded shaft 44 (threads not shown) advances the threadedcheek member (threads not shown) against an end of the spring member 31,

Variations in the spring compression, it will now be seen, allows thepressure of the water of the sea in th'e metallic bellows to move theaquaplanes through a more or less angular degree, and therefore to givea greater or less sub-surface travel or navigation of the fish Since theaquaplanes are pivoted centrally, and since therefore the water pressureimpressed upon both sides is equal when the fish is under way in thesea, it requires but little power to alter and h'old the angle of lead.Applicant has shown this to be a fact with the model reduction topractice which he has carried out.

The cases 46, 4E and 41 contain step-down transformers, storagebatteries and control apparatus as well as servicing equipment andsupplies (not illustrated in detail, but necessary or desirable in theoperation of the sh).

48 is a small electric motor fashioned to be operated by power from thecable or a storage battery and controlled by a filter, relay, switch andthe like by carrier current for rotating at will by remote control itsthreaded shaft 49 and thereby releasing the threaded draw-bar member 50which acts as the connecting towing member for the cable attached to theleading member (not sh'own in the present illustration) of theprotective belt. This motor operated device to enable a ships master torelease the protective belt at any time and thereby possibly cast itadrift should he ever wish to do so. It has been learned that somesea-faring men might wish to have such a ship clearing gear. Here 52 isa, motor driven sump-pump for removing any sea-water which may enter thecasing of the electric fish through stuffing boxes, manhole covers,cable entrances and the like through the system of piping substantiallyas illustrated, and 53 is the casing containing the necessary controlequipment and supplies for this sumppump, and such other gear necessaryto th'e operation of the electric fish.

54 is a motor operated winding drum for the interconnecting strandedcable or wire for counter magnetic mine work, as will be clearly dealtwith in subsequent views. 55 is a water-tight revolvable insulatedstrain anchor for a power cable 56, and 51 is a xed insulated straininsulator for the cable 58, which may or may not be an electricalconductor, according to the particular design of system employed. Wheredirect current is employed instead of three-phase alternating current,the system is simplified, the cable 58 being a combined electricalconductor and strain cable, the conducting metal or copper in this cablehaving a steel core. Such a cable is commercially .known as a copperweldand copperweld-copper conductor, having tensile strengths of from 2 to21/2 times the strength of hard-drawn copper. The compound conductorcomprises a thick weld-on covering of copper, which gives the highstrength of steel without danger of rusting in the salt water of thesea. The electrical conductance is the best obtainable of any hightensile strength conductor and the applicant has full necessary data forthe power transmission requirements. 59 and 60 are openings Vinto thesteel shell 25 in order that cooling sea water may contact the housingsof the motors 26 and 21 when they are too small to fit snugly into theshell, being held by the welded members 6I and 62.

It is deemed 4of pertinent interest to state that these motors are heavyduty variety, glass and asbestos insulated, with bearings of ball orroller type packed in heavy grease, for long voyages wit-hout attention.

In addition to the air fan cooling or/and water cooling, a watercirculating pump may be added for each motorr (not shown forsimplicity). The voltage of the present S-phase induction motors is ofthe order of 2200 volts, and the current may be standard 60 cycles. Thediameter and pitch of the propellers have been worked out to operatedirect connected at 1800 R. P, M. for various speeds of cargo vesselsand the horse powers required to tow the belts, all based upon actualand practical data in hand. But a full engineering exposition would beoutside of a patent specication. Suflice it to say, however, that fortwo three hundred horse power motors, as illustrated, in the presentelectric iisl'i, a pair of 30 inch turbine propellers 14 inch pitch,three blade, on 2 inch diameter shafts, would not be far from thecorrect mark for a 10,000 ton 12 knot freighter, and its protectivebelt.

With further reference to Figure 2.

Here it is pointed out that the movable aquaplane 3% on its shaft 42,adjacent to the forward end of the fish, is substantially centrallypivoted in order that the water pressure of the sea is substantially thesame upon an area before vand aft of the shaft, thereby rendering iteasy of angular control. In other words no undue turning effort isrequired of the metal bellows gear to hold or alter the angle of theaquaplanes when the electric fish is under way in the sea. Actualexperiment with models by the applicant has shown that this simplemethod of depth control is correct, but it is barely possible for thefull sized electric ish, that electric motor'control may be moredesirable, in which case working data may be easily obtained. In thisview it is also pointed out that the twin aquaplane 3S'is xed adjacentto the rear end of the iish, and experiment with a power driven modelsubmarine towing a model belt has shown that a pair of such Xedaquaplanes are quite essential in View of the mechanics of pull andother forces atwork, of the entire submerged system. The angle and areaof these xed rear aquaplanes 3S has also been found by experiment to beimportant, especially important in connection with the applicants designof leading rudder. for the ish.

In his model reduction to practice applicant has many data of interestand value in connection with the submarine belt system, but itV isdeemed to be outside of this specification to indicate them all here.

Themultiplicity of openings 59 and 60 through the shell of the fish is,as stated, to allow the cooling water of the sea to carry away the manythermal units of Watt dissipation of the electric motors, transformersand the like within the shell of the electric fish.

The opening 60' which may, or may not, comprise an insulating bushing,and which is centrally located as will be seen, serves for the entranceor exit of a cable or wire for the series connection of the motors inthe two electric fish, and also as the source of a magnetic eld in thesea capable of operating the magnetic mechanism of a magnetic mine. Theeye bolts 25 25 are suitably screwed into the field casings of theelectric motors, to aiord approved lifting points, if, as and when itmay be desired or required to hoist the electric fish out of the sea andto swing it upon davits or the like.

With further reference to Figure 3.

Here it is believed that the features in the two foregoing views aremade additionally clear and that further description is not necessarysince like parts bear like numerals in all of the illustrations.

With further reference to Figure 4.

Here 65 is a plan view of a ship equipped with my proposed stanchions,or projecting platforms 66 and 61, which may be pre-fabricated and bequickly bolted to the sides of a ship. They are somewhat analogous tosmall gun platforms as applied to gun-boats and cruisers, but instead ofpivotally mounting a gun carriage for angular sweep, they pivot at 68and 68 substantially counter-balanced, yieldable, angle-controlling,motor-operated winding and paying out drums S9, 10, with the counterbalance members '10', 10', each drum fashioned to receive one or morecables 1I, 'Il' for supplying electric power and carrier currents to thesubmerged electric fish 25, 25, which electric fish tow the submergibleand submerged torpedo belts 12 and 13 by means of the cables 5|, 5|. Aspreviously stated, upon wired radio impulse of proper selectedfrequency, electric motors in the electric fish? may be made to unscrewand release the belts, one or both, from the electric iish at the willof the skipper on the bridge of the ship 65.

The skipper may also, through the means of hand gear on the windingdrums 69, (not shown here but in a later gure) send the electric fishfurther out into the sea, as indicated in the dotted lines `5|', 5l',whether they are towing torpedo belts or not. In the drawings no torpedobelts are shown in the furtherout position, because applicant may towone of a number of alternate protective devices. For example, applicantmay tow one of the compound net sheathed belts as later illustrated anddescribed in detail, or he may tow a large meshed steel net fashioned toensnare the tail of a torpedo in the act of passing through. Such alarge meshed steel net offers less towing resistance than. a compoundbelt, but it has the disadvantages of possibly fouling a screw propelleron making a hard port or a hard starboard turn, and in addition couldfail to ensnare a fish torpedo by the tail if said tail is properlyguarded in the future.

Applicant may also elect to tow an explosive device fashioned todetonate the explosive in a torpedo warhead when it approaches thedevice or contacts it. Such an explosive ,device fashioned to be towedwill be more fully described later in this spe'ciiication.

Still another alternate device would be a loop, towed well out from thesides 'of the ship and well astern thereof for successively tripping themechanism in a magnetic mine. Another alternative would be long cableselectrically conducting direct currents for counter magnetic minedestruction. All of these alternate devices would require less towingpower and consequently smaller electric fish.

For such comparatively small electric sh a smal1 steam turbine operatinga generator could well be run with a minimum of space by taking steamfrom the ships boilers.

Electric power, either alternating current three phase, 60 cycle, ordirect current, is generated by the Diesel engine generator set 18, vandcan be supplied to the cables 'H and `1 I by suitable regulating gearand leads (not shown in the present drawings). In this Diesel enginedrive, the speed of the ship at sea is not reduced. The weight of theDiesel engine generating set is negligible in the matter of the shipsdisplacement. In other words tons or more in a 5000 or 10,000 ton shipwould not affect her speed as much as a slight change in theVtemperature of the sea in which she navigates. excess power over thetowing power required of the belts would of course tend to increase thespeed of the ship. The electric power may be supplied, however, by asteam driven turbo-generator set, in which case there would be areduction in the speed of the ship, or the power may be taken from thesteam electric drive of a ship by a simple bleeder system.

In the case of taking power from the ships electric drive it may bestated that in many cases the boiler plant may well stand this eXtrademand without reducing materially the ships speed. Again it might besimpler to add an auxiliary boiler than to add machinery-a Dieselelectric generating set, for example, if this was found necessary onclose calculation.

At 'I9 is a complete duplicate set wired radio transmitting equipmentfor sending carrier currents at different selected frequencies over thepower cables, or over the power cables and salt water of the sea,comprising oscillators, condensers for selective current transmittersand the like for the remote control of the mechanisms in the electricfish as already described. The wiring or connection to the winding drumson the power cables and the grounds to the sea arenot shown in thisfigure. Y

With further reference to Figure 5.

Here the important scheme of one of the pair of stanchions andcounterbalanced, motor operated, pivoted, yieldable, angle controlling,winding 'I'he addition of the slight and paying out drums 'l0 is madeclearer. The counterbalance member 'l0' not only counterbalances thedrum, but the cable extending into the sea. The drum is restrainedagainst sudden or short duration pulls of the cable and otherdisturbances, as from the roll of the ship, by hydraulic check cylindersnot shown in the present View but illustrated in a subsequent view.

With the present ship G under way, the electric sh 25 and the protectivebelt 'k3 are shown below the level of the sea, both being capable ofbeing sent still lower-below the deep troughs of the waves of the sea-instormy weather.

Both fish and belt therefore are not only automatically regulated forfixed depth of navigation, but are controllable for variable depth ofnavigation by remote control through the agency of carrier currents inthe wired or guided radio.

The electric iish has the pair of controlling aquaplanes, one of whichis shown here at 36, and the belt device, later described in detail, hasa plurality of automatic depth controlling aquaplanes 8D, '89, 8G,presently illustrated and described in detail. The ruddermember 82 ofthe forward end of the belt 'i3 is equipped with a pair of stabilizingpivoted aquaplanes 83, operated by a gyroscope driven by cable power orstorage battery, to insure vertical position in the sea when under tow,or by mechanical means comprising a pendulum hinged to a, beveledpinion, which turns a pair of bevel gears, respectively, turning portand starboard aquaplanes, all as illustrated and described in a brochureentitled New Torpedo Proof Convoy for Freighters at Sea, written by thepresent applicant and a matter of record at the Massachusetts Instituteof Technology, Johns Hopkins University, and Stevens Institute ofrTechnology.

Of course applicant has given due attention to the power required of hiselectric fish to tow such a belt 13 of various widths, and lengths, andat various speeds in the sea, taking into account th-e power requiredfor the depth controlling aquaplanes. This has involved a study of thevalues of skin frictions, not only of ships, but of various materialsconsidered for the sheaths of his net enclosed belts. The belt isadjusted to be barely floating when at rest, therefore the aquaplaneexertion, and consequent power therefor, to overcome the aquaplaneexertion, is not great. The fact has been well determined by applicantsmodel belts. Also engineering calculations have been made of theresistance to towing of a smooth surface in salt water, based uponWilliam Froudes classic formula:

R=fsv" where R=resistance in pounds s=area of both sides f=coefcient offriction U=knots 11:1.83 exponent face is one of the least resistant,according to extended researches, to towing in the salt water of thesea.

The drawings, details of which will be shown in subsequent views, havebeen made from model belt construction, which construction lends itselfto any desired width of belt-from let us say, for example, 8 to 12 feetor more.

An eight or ten foot belt navi-gating l5 feet below the surface of thesea is as effective a barrier to the fish torpedo, it will beappreciated from the present illustration, as a much wider belt With itsupper edge at water level, and, of course, the narrower the belt for anygiven length, the less will be the skin friction and consequently thepower required to tow it.

Thus it may be seen that the ship may wallow in a heavy sea, with theminimum of strain and stress upon the cable 1| and with practically nostrain and stress upon the deeply submerged or submergable electric shand protective belt.

With further reference to Figure 6.

Here Imore or less schematically represented is a side view of one ofthe large winding drums slidably or yieldably mounted through the agencyof its hollow axle 90 and sliding bearing member 9| in the long slottedguideway 92, which bearing member is resiliently held back toward thehollow central pivoted shaft 68 by means of one of a pair of lug members93, and the long bar members 94 and the distant head member 95 'and thelong compression spring 96, in the long cylinder 9S.

The long bar member 9d terminates in the conically turned end 91fashioned to make an electrical circuit closure by contact with theadjustable spring members 98 and 99 fashioned to be moved forward orbackward by the screw |66 and its hand wheel il. Electric current in theconductors |02 and |03 may be made to flow therefor when the conical end91 of the long bar member 911 recedes. The conductors |92 and |03 leadto a source of electric current and a proper power controlling devicefor current to theaforesaid mechanical electric fish.

The hollow shaft S8 is stationary with the pedestal |66 secured to theplatform or stanchion 61 by the bolts ll, said shaft extending upwardlythrough the carriage Illfl for the winding drum, which carriage restsupon the heavy radial and thrust bearing |05 recessed in the upper partof said pedestal.

A flexible insulated electric cable |08 extends from the connections tothe cable in the drum 'l0 to and down through the hollow central pivotshaft 68 and is conveniently available in a stationary anchorage at |99for connection to a suitable source of electric power for thepropulsion` of the motors of the electric fish in the sea.

With further reference to Figure 7 Here the drum is shown in partialsection to show the reception of four cables-three insulated copper orcopper weld steel, power transmission cables, and one bare steel tensioncable, possibly consisting of copper plated strands or impregnated withanti-rust compound, for removing all under strain from the insulatedcopper cables.

ent mechanical cable for strain purposes. For example, there would lessstrain on the insulation of three comparatively small cables, than uponthe insulation of one comparatively large cable.

The cable drum is provided with one or a pair of similar large gears |09and ||0 positioned and attached to engage the small similar pinions and||2 of the reversable electric motor |3, supported by the casting |00.Proper electric wiring, switches and starting gear are naturallyunderstood to be present but not illustrated in the interest ofsimplicity.

The housing ||4 for the three slip-rings and brush gear ||5 for theconnection of the conducting cables to the electric sh is madeindependent of the revolution of the drum through the slip-rings andbrush gear at l 6 which represents the exible cable |08 of the previousview.

The double-armed yoke member ||'l, being rmly attached to the hollowshaft $8 remains stationary when the casting |04' turns to the right orleft when so led by the tension of the cables running to the electricsh, but the distance through which it may move together with its rate isregulated by the piston rods pivoted at |20 and |2| to the arms of thedouble yoke member IH. These pivoted piston rods play in and out of thecylinders |22, |23, pivoted at |24 and |25, respectively. The pistonheads |26 have one or more minute passages bored through them (passagesnot shown) to allow the restricted passage of a non-freezing fluid |26to pass through them. These control cylinders and enclosed pistons andfluids prevent the rapid movement of the drum carriages, as for instancein the roll of a ship in case the cable drums and more or less cablewound upon them, were not precisely balanced by the counterweights Inother words, only a prolonged pull of the cables from the electric fish,from right to left or from left to right, respectively, would cause thedrum carriage to alter its position, and thereby the position of thetongue member |30 and its spadeshaped end member |3| which is positionedbetween the duplicate sets of electrical Contact making spring members|32, |33, which spring members may be advanced or retracted through theagency of the insulated gear with screw threads and hand wheels |34andrl. Thus it will be appreciated thatra steady and prolonged pull ofthe electric iish to the right or left, and only a steadyr and prolongedpull, will cause the spade-shaped head member |3| to close with theright or left contact making spring members. It is through these rightand left Contact making spring members, that the oscillator transmittersfor the wired radiolcarrier currents, to the filtered relay, ampliersand switch gear of the reversable electric steering motor in theelectric sh, are started and stopped. It is not deemed necessary ordesirable to illustrate the complicated connection here, in theinterest'o'f simplicity; suice it to say that the comparatively highfrequency carrier currents are led into and out of the power cables ofcomparatively low frequency through condensers indicated schematicallyat |38 and |39. By means of the hand wheels I3@ and |35, it now becomesevident'that the closeness of the control of the electric fish in theirSteerage way in the sea'may be eiected, and when necessary or desirablemay be'manually controlled, by simple auxiliary circuit closures andopeners (not shown in the drawings).

lWith further reference to Figures 8 and 3.

Here the ship 65 again shown in plan view is equipped with somewhatsimpler and narrower, counter-balanced winding drums, for the receptionof a single conductor electric cable, insulated' for direct current at2500 volts, for example, the drums being shown in a reversed directionof pay-out over those shown in Figures 4 and'5.

The present equipment may, or not, comprise a torpedo arresting ortorpedo destroying belt 'l2 vand 13 with its cables electrically chargedfor magnetic torpedo warhead or magnetic mine destruction, and with orwithout the rear or trailing loop shown specically in Figure 9.

The present equipment may in an alternate case comprise the aforesaidloops and its depth controlling auxiliary shown in Figures 4 and 5 andinstead of the belts 'l2 and i3 shown in the dotted lines, merely one ormore of the cable elements of the belts may be employed for the purposeof establishing magnetic fields in the sea for the operation of magneticmines (indicated at Il) and the like, especially the magnetic warheadsof this later design of sh torpedo. In the case thebelt is used,however, one or both of the mechanical cables in the belt construction,later illustrated and described, may be insulated electrically and be sointerconnected in circuits as to act as combination power cables for theelectric fish and magnetic mine and magnetic warhead torpedodestroyers-particularly the latter, since the equipment may be sentdown, by remote control, or otherwise tonot only depths just below thetroughs of waves in the sea, but far below them to depths greater thanthe drafts of the deepest ships hulls.

In the present View a steam turbine electric generating set is shown at|40, the electric generator being of direct current design, and possiblyof the three wire typeV for grounded neutral. This generator may producedirect current with proper commutator design, of 2500 volts, for eX-ample, and be connected in series with all four of the electric motorsin both of the electric sh as shown.

There is no difficulty in generating and commutating direct current lat2500 volts, a system exemplied by the practice once, if not now, invogue with certain Swiss railroads, for example. The current in thisinstance will be for the four 300 horsepower` motors as indicateddiagrammatically in the location of the'two towing fish at 25, 25, ofthe order of 260 amperes, and the copper conductor of the cable mayconsistof twenty strands or more of copper wire aggregating in circularmills that of a No. 0 wire A. W. G., or preferably such a strandedconductor comprising copper-weld construction for high tensile strength,a subject already dealt with in this specification.

It is of course understood (although not shown) that suitable switchgearis installed for the electric generator set |40. When this is analternating current equipment we would require the proper generatorpanels, direct current exciter panels, bus tie, in case two sets ofgenerators are used, and a synchronizing panel.

To secure variation in the towing power 'of the electric fish we must ofcourseV have means for varying the speed of the electric motors, and itis provided to secure a range of 50-100 per cent speed. This can readilybe accomplished by means of engine governor control through electricalconnections to the leads |02 and |03 of the Vvided for the leading loop15.

cf'iunterbalancec'i winding drums, illustrated and described in Figures6 and '1.

In order to maintain an alternating current generator voltageproportional to the speed, it will be necessary of course to provideways and means of holding its exciter voltage constant over the speedrange. This applicant can do this by furnishing an exciter capable ofmaintaining rated voltage over the 2 to 1 speed range and then use avoltage regulator, operating in the field of the exciter to holdconstant exciter armature voltage. A diactor type of voltage regulatorwill serve this purpose. When the electric generator |40 is of thedirect current type, the question of variation inthe towing power of theelectric fish -is even simpler to handle through the agency vE5 for theprotection of a vessel following in the wake against one or moremagnetic mines.

There is not room enough on the drafting sheet to illustrate Vsuch aloop, in Figure 8, but it is clear that one may be towed as an extensionof the conductors of the belt 12, 13. With a loop t towed astern, thecenter of the loop may have a depth controlling device 11 such as thatpro- Moreover, it may have an independent towing cable 15" attached to aring at the stern of the ship, to prevent the loop from becoming toonarrow in form to be effective. In the case a loop is towed aft, theship towing it relies upon her degaussing system to protect her frommagnetic mines. The useful object of the loop towed astern, is to trip'the mechanism in a magnetic mine and explode the same before a shipfollowing may be blown up. Applicant may tow one or more loops (15 and15") astern, with distances between them, to give one or more magneticdisturbances to a magnetic mine, since some types of magnetic minesrequire one or more magnetic disturbances to set,

them off.

rPhe rear loop may be in series with the entire vsystem or be in anindependent circuit. When the leading loop 15 is not used, and a reartrailing loop behind the ship is used, a return conductor from theelectric sh is of course installed. -All of the wiring and connectionsare so simple and so readily understood by electrical engineers,

that detailed diagrams are not given here.

Thedistance out of this belt device 12, may also be controlled by somealternate design of radiant energy control M5, using an approved radiantenergy projecting and responsive system, respectively, with suitablechronograph Y'time factor measurement and control system.

Sound, light, heat, electromagnetic waves, and the like may be employedhere on the range- 'nding and deep `sea sounding principles, 'for eX-ample. Such a system could be devised to act as anwalternate plan ofcontrol for the wired, or guided radio remote control of the responsivesteering devices in the electric fish.

r'The diagrammatic representation of the electric fish 25, 25 in theseviews includes the diagrammatic representation also of the'wired radioYsteering gear, showing the motors l35, 35, the ,.storage batteries 35',35', the rudder-s and gear,

magnetic mines.

32, 32, and the condens-ers, grounds and other necessary devices at 35",35".

With the present direct current equipment. it is possible through theagency of an oil immersed pole changing switch (notshown) at thegenerating set |43, to reverse the current flow through the entirecircuit at will, without of course reversing the direction of rotationof the motors 26 and 21, because it reverses both in the fields andarmatures. Since this is an important feature in operation formagneticmine destruction, applicant deems it pertinent to explain that toreverse an electric motor of the direct current type, the currentsupplying it must be reversed in either the iield or armature, but notin both. Since we are by the nature of the electrical connectionsreversing the current in both when we interpose the pole changingswitch, we do not reverse the motors, andconsequently the propellers orthe direction of motion of the fish 25.

By reversing the current in the entire system at intervals, however, wereverse the magnetic polarity at the magnetic fields in the sea, andthis may serve as a valuable feature in exploding Some magnetic minesmay be fashioned to require such changes in polarity, or they may befashioned to require a plurality of tripping forces in order to explodethem. In other words, this ability to change the polarity of themagnetic fields in the sea, adds to the flexibility and possible broaderuses of the system in designs of magnetic mines yet to be dealt with.

With the loop 15 as a leading series loop with its float or depthcontrolling device 11', its destruction by a mine need not stop theelectric sh for the salt water of the sea could well act as a returnpath for the current, especially if the large metallic shell of the fishV25 has been made one electrode. L

With further reference to Figure 9. Here is shown in simple diagram one'of applicants alternate plans for exploding magnetic mines .for theprotection of a ship following in the wake rof the vessel carrying theequipment. The loop floats 11' may be fashioned for the opening of theloop by the crew of va service launch .and moreover at this junction beprovided with a coil for increasing the ampere turns, yand lconsequentlythe magnetic field at this zone.

With further reference to Figures l0 and 1l. Here is illustrated aforeshortened view of a section of one design of my fabricated,vertically floating, barely buoyant, and consequently yeasily totallysubmerged, submarine low skin friction torpedo-arresting, or torpedodestroying belt devices. The belt device is shown with a por-tion' ofthe canvas removed in order to illustrate better the woven net. In theseparticular views the belt device is for torpedo arresting, because ofthe yieldable hempen net used between the double canvas sheathings, butin an alternate design, a hard strong plane surface may be interposedbetween the canvas sheathings to vdetonate and destroy a torpedo uponimpact. Here are shown factory fabricated wooden float pieces which aremill machined, impregnated with water proof compound and well painted toprevent the absorption of water and consequent change in buoyancy, whichwould impair or destroy the usefulness of the float. yTwo complementallyformed pieces l5!) and I5! of the fabricated and "treated float membersare clamped together .by large wood screws 15H', |51', embracingastranded steel cable 152, positioned rloosely inthe cylinldricalpassageway |53 formed by joining the opposite oat pieces, `both floatpieces being suitably grooved. This cable is here illustrated bare fortensile purpose, but as previously stated for magnetic field purposes,it may be insulated to serve both tensile and electrical conductorpurposes. |54 is a canvas sheathing, comprising -one or more coa-ts ofmarine metallic paint applied upon both sides and simonized by treatingwith parafl'in, since .parailin has been found by researches in towingplane surfaces in water to offer a minimum of skin friction.

Back of this treated canvas is the stout woven net |55, comprising thehorizontal warp members |56, and the vertical woof members |51, thelatter of which run up into the well fabricated grooved clamping space,together with an edge of the canvas |54. |54 is a similar sheathingdisposed on lthe other side of saidl net. The lower edge of thisfabricated belt is clamped between two complementally formed metalsinker members |58 and |58', providing a cylindrical passageway |59therebetween loosely receiving therein the steel cable |6|. 'I'he metalsinker members are riveted together by the rivets |60, |60. This steelcable |6| may or may not be electrically insulated to serve as anelectrical conductor as well as a mechanical strain member, as in thecase of its companion cable |52.

Both of the cables, |52 and ll, respectively, may be copper clad, or beof stainless steel, or be of a combination of these two Ways and meansto prevent or retard rusting in the salt water of the sea.

The vertical woofs |51 at this lower edge of the belt device, arelikewise securely clamped by the metal sinker members |58, as are thecanvas sheathings |54 and |54 by the metal sinker members |58.

With further reference to Figure 11.

Here we have a transverse sectional view of Figure 10 showing clearlythe two painted and lparaiined canvas sheathings |54, |54 necessary tocompletely enclose and to prevent the passage of sea water through thenetwork comprising the horizontal warps |56 and the vertical woofs |51of the net work, as well as the pair of screwed together wooden floatmembers |50 and |5|.

Here we see how the metal sinker members |58 and |58 likewise clamp thesheathings and the warp and woof of lthe net work. At the lower edge ofthis sinker member, in addition to the rivets |60, |60, the metal sinkermembers |58 and |58 are securely united by the U bend |62 of the member|58' embracing an edge of the said member securely.

An inspection of this fabricated construction will make clear the easyand quick assembly of the component parts.

An inspection will also make it clear that'applicant may add any numberof canvas sheathings, or include between them a net work of stouterropes, to meet any requirement ofV impact without increasingthe skinfriction of this design of belt device.

Also it will be appreciated that a steel net may replace the rope net,provided of course the size of theA impregnated and painted woodenfloats are enlarged to care for the added weight of the steel over thehemp rope which latter has substantially negligible weight in sea water.

It will also be apparent that a metal plate may be substituted for -thenet work, and be thick and strong enough to cause the destruction of thetorpedo by causing the detonation of the explo- 'sive charge in itswarhead. Some torpedoes may be fired by the driving in of a contact pinin the War-head, while others must strike a sufficiently resistantsurface so as to cause a sufficiently rapid decelerated rate of motion,to cause an inertia device in the warhead to move swiftly and smartlyenough to explode the detonator.

Y With such a' hard surfaced and strong plane surface between the canvassheathings, applicants belt device consists ofa torpedo destroyingequipment.

With further reference to Figure 12. Y

In this last illustration We have a short length of the same side viewof the belt device, adjacent to the lower or sinker member, as in Figure10.

Attached to the metal sinker member |58, by means of the rivets |65,|65, is the important cigar shaped automatic depth controlling device|10, with conical or stream line ends, fashioned of sheet metal andadapted to not only automatically set and maintain a sub-surface depthwhen its belt device is towed at a set speed, but adapted to becontrollable for one or more Subsurface depths by remote control fromthe ship. Therefore it will now be appreciated that both the electrictowing fish and the ship protecting belt devices, are automaticallycontrolled as to depth of sub-surface travel, and also remotelycontrollable and adapted for one or more sub-surface depths by remotecontrolfrom the ship. This gives the entire equipment ygreat exibilityof use, as will be appreciated -by those familiar with the problemsinvolved in combating great seas at times, and in combating deeplyplanted magnetic mines and deeply launched magnetic warhead torpedoes.

In this cigar shaped device we have the bulkhead member 1|, thecompression spring |12 exerting a balancing pressure against thecompression spring |13, through the medium of the rigid slidable rackdevice |14, with its teeth |15 engaging the teeth |16 on the enclosedgear wheel |11 keyed on the shaft |18, which passes through stuffing boxbearings (not shown) in the shell of the cigar shaped device |10, whichis fashioned to be operative as a depth controlling device when ittravels from right to left in the direction of the large arrow above iton the sinker member |58. The shaft |18 carries exteriorly inthe sea apair of aquaplanes, one on each side of the device, the port aquaplane|19 being shown by dotted lines, said aquaplane for hydrostatic reasonsbeing pivoted at its central zone. As previously pointed out thiscentralpivoting requires the minimum of turning or angle changing, aswell as angle holding power.

An opening into the casing of the device allows the water of the sea toenter the open end of the metal bellows |8|, the opposite end of thebellows being closed to receive the combined thrust of the spring |12and the pressure of the water ofthe sea when the device navigates belowthe surface of the sea. The pressure of the sea water is indicated hereby the two long arrows.

At the right or stern end of this cigar shaped device |10 is the brassor non-magnetic member |82 centrally bored through and reamed toslidably receive the head member |83 for the spring thrust, and an endof the steel rod |14 which is adjustable in longitudinal travel by thescrewV device |15. Y

The solenoid |86, when suiciently energized by .an electric currentthrough its leads |84, |85 of asaoeo its insmatea winding ist', iscapabie of adventing the steel rod member |14 and thereby in increasingthe tension of the spring |13. This combination of steel rod member|14', the solenoid |86 and the spring |13 is in effect a ruggedamperemeter, and is capable therefore, through the toothed rack |14 andthe toothed wheel |11 Ato turn thev aquaplane |19 against the'pressureof the spring |12 and the pressure of the water of the sea in the metalbellows |8I, which may be made of brass or stainless steel, in acontrollable quantitative manner through the agency of a storage batteryand rheostat on the ship. Now as the depth of travel of the deviceincreases in the Water of the sea, the pressure of the water in Atheinterior of the metal bellows correspondingly increases, andconcurrently the pressure in opposition to that of the remotelycontrolledtension of the spring |13 also increases, and therefore itbecomes apparent that applicant has an automatic depth control devicefor his protective belt and in addition one for remote variable depthcontrol. Y j

It is obvious that those skilled in the various arts and sciencesinvolved as herein set forth, may vary the details of construction andarrangement of parts, as well as the methods, ways and means of theapplicant which enable him to produce the foregoing new and usefulequipment for the protection of ships, without departing from the spiritof this invention, and therefore it is not desired to be limited to theprecise foregoing disclosures, except as may be required -by the claims.

Having described my invention, I claimt l. In combination a submarinetow boat cornprising a depth controlling device, a motor for activatinga propeller on said tow boat, and means operable from a remote point forenergizing said motor and for controlling the movement of said tow boat;and a protective device fashioned to guard the hull of a ship fromsea-submerged eX- plosive contrivances, said protective device having aflexible connection with said tow boat whereby to be towed at aconsiderable distance therebehind, said device provided withhydraulically and electrically actuated means for controlling the depthof said device in the water of the sea.

2. In combination a submarine tow boat comprising a depth controllingdevice, a motor for activating a propeller on said tow boat, and meansoperable from a remote point for energizing said motor and forcontrolling the movement of said tow boat; a protective device fashionedto guard the hull of a ship from sea-submerged explosive contrivances,said protective device fashioned to be towed by said submarine tow boat;and remote control means for varying the depth of navigation of said towboat and said protective device, said means comprising aspring-tensioned aquaplane responsive to hydraulically and electricallyinitiated pressures.

3. In combination a submarine tow boat comprising a depth controllingdevice, an electric motor for activating a propeller on said tow boat,and a remote controlled rudder on said tow boat; a protective devicefashioned to guard the hull of a ship from a submarine explosivecontrivance, said device adapted to be towed by said tow boat; anelectric cable connected to said motor and leading to a source ofelectric power on such ship; and cable receiving means disposed at theside of such ship, said means controlling the angle of lead of theremote controlled rudder of said tow boat in ysure responsive depthregulator for the tow boat,

cable fashioned to supply accordance with the angle made by said cablewith the side of such ship.

4. In combination a submarine tow boat comprising nected thereto, arudder at the bow fashioned to be operated by electric remote control,and a pressaid regulator subject to variation through electric control;and a cable for supplying electric currents for energizing said motor,for operating said rudder, and for variably controlling said regulator,said cable leading to a source of electric currents remote from said towboat,

5. Apparatus for protecting the hull of a ship from submerged mines andtorpedoes, comprising a protective screen for said hull, a tow boat fortowing said screen in spaced relation to said hull, and means forvariably controlling such spaced relation as well as the direction anddepth of navigation of said tow boatv and said screen, said meanscomprising an electric cable connecting said tow boat with a source ofelectric power on such ship.

6. In combination, a submarine tow boat comprising a depth controllingdevice, an electric motor for actuating a propeller on said tow boat,and a remote electric current controlled steering device for said towboat; an electric cable extending from said tow boat to a source ofelectric power, one end of said cable fashioned to supply such power tosaid motor and to said steering device; and a yieldably mounted memberreceiving the other end of said cable and fashioned to connect it withthe source of electric power, the yieldable mounting of said membercomprising control means for the current from such powerrsourceto saidtow boat. Y

-7. In combination, a submarine tow boat comprising an electric motorfor actuating a propeller on said tow boatMand a remote electric currentcontrolled steering device for said tow boat; an electric cableextending from` said tow boat to a source of electric power, one end ofsaid such power to said motor and to said steering device; and a currentcontrolling motor operated winding drum receiving the other end of saidcable and fashioned to connect it with the source of electric power, andsaid drum responsive to the tension exerted by said cable and therebycontrolling the current to said tow boat.

8. A motor operated winding drum for an electric power cable and adaptedto pay out and` to wind in said cable at will, said drum comprising anaxle and a counterbalanced pivoted support therefor, said axlecomprising slip-rings and brush gear for an end of said cable, -saidsupport comprising a cylinder, a piston and a fluid in said cylinder forretarding the movement of said support but fashioned to allow saidwinding drum to turn and assume a position in line with the direction ofpull of said cable with respect to said drum.

9. A motor operated winding drum mechanism for an electric cable,comprising a drum, an axle and an electric motor therefor, a slidablebearing for said axle, a pivoted support for said bearing, a springretarding the slide of said bearing, and a counterbalance for saidwinding drum.

10. A cable winding drum mechanism for a ship, comprising a stanchionsecured to the side of the ship, a pedestal mounted on the stanchion, arevolvable bearing in the pedestal, a substantially counterbalancedcarriage mounted on said bearan electric motor and a propeller con@ ing,and a `motor operated `cable winding .drum mounted on said carriage.

1.1. Apparatus for'protecting the ,hull of a ship from submergedmines-and torpedoes-comprising a tow boat having electricallycontrollable .pro-

.12. Apparatus for protecting thehulltof a ship i from submerged mines.and torpedoes-comprising a tow boat having electrically controllablepropellent and navigation direction means, .aprotec- .tive screenattached to said tow boatl forytowing thereby in laterally-spaced.relation to such ship, asource of electric `power :on suchship, .and...a winding drum mechanism for said cable mounted at the sideof such`ship .and .controlling lthe angle of lead of said tow -boat KinIaccordance withthe :angle Imade by said .cable with the .side -of theship.

.13. ,Incombination-a submarinetow boat comprising a depth controllingdevice, za 4motor for actuating fa Ypropelleron .said `tow boat,.andmeans operable -from .a .remotepoint 1for energizing said motor and forcontrolling the movement oir-said tow boat; a .protective .device tforthe side-of a ship, said .device secured fsolely to `and ltowed by saidtow boat in spaced :disconnected relation -to such ship; an electriccable connecting said .tow boat and the ship for supplying currents-toener- .gize said means; :and'radiant energy -means for .measuring theydistance vof .-'said :protective .device ,from the side of -the ship,and to .substantially -automatically maintain :such measured distance.

14. -An -electric Acable -windingdrum lmechanism V'for a rship,icomprising .a rpedestal secured -to said rship, a fshaft :mounted-vertically vin sai-d `pedestal,

.a carriage mounted -on said shaft -and extending ihorizontally .inTopposite directions therefrom, .a cable rwinding @drum lslidablymounted yinzone end 'portion ofsaid carriageand under spring tension Itoybe responsive to kthe pull of the-cables, coun- V'terbalance for saiddrum rmounted von the opposite end of said carriage, and means forsupplying .electric currents `to-thecable Wound on said drum.

15. In combination asubmarine "tow 'boat1comlprising a ydepthcontrolling device, fanfelectric .mo-

.tor'foractivatinga -propeller onfsaid ftow.boat,;and

v'a .remote controlled rudder-on .said .Itow =boat; la .protective4device vfashioned to guard the hull .of

.favship from a submarine .explosive contrivance, said device adapted tobe :towed by saidtowrboat; an electric cable connected to said motor and.leading to a sourceofrelectric power on such ship; andY .radiant energyVmeans for maintaining .spaced relationship betweensuch ship and saidprotective device.

l16. Incombinationa submarinetow boat comprisinga depth controllingdevice, an electric motor for activating a .propeller on said tow boat,and-aremote .controlled rudder on said tow boat; .agprotective devicefashionedtoguard-the hull .of a ship Afrom .a .submarine explosivecontrivance,

`saidldevice adapted `to be towed by said tow boat;

`an .electric fcable :connected yto .said motor -andleading.torafsourceof electric power on such-ship; .and -phonic .meansfor maintaining spaced .relationship ,between such ship and -saidprotective device. I

1.7. iIncombnation a submarine vtow .boat com- .pr-ising -a depthcontrolling device, fanelectricmo- .torifor activating a .propeller Ionsaid itow boat, and a remote controlled rudder on said -,towboat; fsaprotectivedevice -fashioned rto guard .the yhull of .a ship .from -asubmarine explosive contrivance .saiddevice adapted tto rbe towed vby:said 4tow boat; :an electric cable :connected to said motor and leadingvtofa source of yelectric power@ on such ship; Aand electromagneticfmeans for maintaining .spaced relationship between such ship :and -said.protective device.

18. lInfcombination asubmarine tow boat comprising a depth .controllingdevice, an electric motor for activating a propeller Onsaid'tcw'boat,and a remote .controlled frudderfon said tow fb'oat; .a vprotectivedevice :fashioned -to guard 'the -hull of -a ship .from .a `submarineexplosive 'contrivanca said device adapted to be -towed by-saidztowboat; van electric Acable connected .to :said motor and leading to v.a-source of lelectric power on `.such ship; .and vibratory meansfor-maintainingzspaced relationship between such 'ship andSai'dfprotective rdevice.

19. vIn 'combinationzasubmarine tow boat :ccml ,prising afdepthcontrolling device,fan electric -mo- A'tor -for vactivating a propelleron said ltow boat, and -a remote controlled rudder onsaid 'tow boat; aprotective device yfashioned :to 'guard'..the hullaof .a vship .from 1a'submarine explosivetcontrivanca `said device adapted to be towed bysaid towboat; :an :electric cable `connected to lsaid `motor .andleadingto a source of electric Apower Aon such ship'; land variabledistance remote control means for maintaining .spaced relationshipbetween such .ship Eand said protectivezdevice.

MONRGE :HGPKINS

